docs: Add maintenance update about starship

[matchai]

Description

Because of the news detailed in #187, efforts have been put into the development of https://github.com/starship/starship. This PR adds a notice to the top of the README explaining that to existing and future spacefish users.

📝 Click here to see the updated README.md

Motivation and Context

Closes #

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Screenshots (if appropriate):

How Has This Been Tested?

• [ ] I have tested using MacOS
• [ ] I have tested using Linux

Checklist:

• [ ] I have checked that no other PR duplicates mine
• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [ ] I have updated the tests accordingly.

[matchai]

:tada: This PR is included in version 2.7.0 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: